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Notes: In this paper the basic pathogenesis of cholesterol crystal embolization (CCE) is described, its clinical characteristics are presented and diagnosis and therapy are discussed. The main focus will be on the cutaneous manifestations; however, considering that CCE is a systemic illness, findings in other organs will also be highlighted, particularly the commonly involved renal and gastrointestinal systems.

Notes: Topical 5-fluorouracil has been used as an effective treatment for porokeratosis. Upon its treatment, an inflammatory effect occurs with the topical 5-fluorouracil. We report a case of a patient with disseminated superficial actinic porokeratosis displaying a comparable inflammatory process following therapy with systemic 5-fluorouracil used to manage a metastatic breast cancer.

Notes: Background: Over the last two decades, there have been a number of studies in Europe on contact sensitivity in patients with chronic leg ulcerations with a frequency of positive patch test results ranging from 40 to 82.5%. The prevalence of sensitization has not been studied in North America. Furthermore, many of the newer dressings and wound care products in the market have not been studied for contact sensitivity in patients with chronic wounds. Objectives: 1) To determine the prevalence of allergen sensitivity in patients with history of leg ulcers in two North American study centers, 2) to compare our results to the European studies and to the North American Contact Dermatitis Group (NACDG) database and 3) to help delineate a standard battery of allergens for patch testing in North American leg ulcer patients Methods: 54 patients with an active or past leg ulcer were prospectively entered in the study. The patients were patch tested to both the NACDG Standard series, as well as, a comprehensive supplemental series of 48 allergens including wound care medicaments and dressings. Results: 63% of patients were sensitized to at last one allergen. The most common allergens were Balsam of Peru (29.6%), bacitracin (24.1%), fragrance mix (20.4%), wood tar mix (20.4%), propylene glycol (13.5%), neomycin sulfate (13%), benzalkonium chloride (13%), carba mix (11.1%), nickel sulfate (11.1%) and Duoderm CGF (11.1%). Duoderm CGF was the most allergenic dressing in our study group. Conclusion: There is a high incidence of positive patch tests in patients with past or current leg ulcerations. Using a modified leg ulcer series along with the standard NACDG series is very important in evaluating patients with leg ulcers.

Notes: We have measured the plasma levels of somatomedin-C (SM-C) or insulin-like growth factor I (IGF-I) in 13 patients with progressive systemic sclerosis (PSS) and age and sex matched healthy controls. We found the plasma SM-C levels to be within normal limits in all the patients. Thus, if somatomedin-C plays a role in the pathogenesis of PSS, it is more likely to be at the fibroblast receptor level or in the synthetic response of fibroblasts to SM-C.

Notes: Confluent cultures of dermal fibroblasts from patients with progressive systemic sclerosis (PSS) and healthy controls were investigated for the synthesis of glycosaminoglycans (GAG) in response to a platelet release fraction (PRF) obtained by treatment of pooled platelets from normal individuals with adenosine 5′-diphosphate (ADP). PRF, at concentrations of 1 to 50 μg protein/ml, produced a linear increase in GAG synthesis that was always greater in cultures of PSS fibroblasts than in cultures of normal fibroblasts (P 〈 0·001). A partial inhibition of GAG synthesis was observed with 100 μg/ml of PRF. The increased GAG synthesis in cultures incubated with PRF was not due to ADP. These findings demonstrate a difference in response to PRF between PSS and normal fibroblasts and may reflect an increased responsiveness of PSS fibroblasts to platelet factors.

Notes: Confluent cultures of dermal fibroblasts from the involved skin of systemic sclerosis patients (SF) and a matched skin site of normal controls (NF) were investigated for the synthesis of glycosaminoglycans (GAG) in response to various concentrations of human platelet homogenate (PH). Experiments were carried out in the presence of 1% and 15% human serum (HS). In the absence of PH, GAG synthesis was higher in SF than NF. An increase in GAG synthesis was demonstrated in both SF and NF as the concentration of PH was increased to 200 μg/ml of growth medium. The PH-stimulated GAG synthesis occurred in 15% HS treated SF and NF, but there was no GAG synthesis increase in 1% HS-treated NF. The absolute count of GAG synthesis was always greater in SF than NF. The addition of PH in concentrations higher than 200μg/ml led to cell death of both SF and NF. These findings are the first to indicate a difference between SF and NF response to PH.

Notes: Background Several extracellular matrix genes, most notably α1(I) and α1(III) procollagen, are reported to be co-ordinately expressed in cultures of dermal fibroblasts. However, it remains unclear whether the expression of these genes is truly co-ordinate or whether it may be the result of averaging the phenotypic expression of different fibroblast subpopulations present within each culture. Objectives To determine by Northern analysis the correlation between α1(I) and α1(III) procollagen mRNA levels in clonal populations of human dermal fibroblasts. Methods As previously described, clonal cultures were derived from parent strains of human dermal fibroblasts by a microscopically controlled dilution technique and by stimulation of single cells with low oxygen tension in the early phases of clonal growth. Results In agreement with previous reports, we found that baseline steady-state levels of α1(I) procollagen mRNA were co-ordinately regulated with the α1(III) procollagen mRNA in 26 parent strains (r = 0·9003; P 〈 0·0001). However, this close correlation between the expression of these two procollagen chains was absent in a total of 40 unselected clonal strains derived from four of the parent cultures (r = 0·5745; P 〈 0·0001). Moreover, this intrachain heterogeneity in α1(I) and α1(III) procollagen mRNA levels in clonal cultures was statistically significant from that measured in parent strains (P = 0·0016). Conclusions α1(I) and α1(III) procollagen mRNA levels in clonal cultures do not show the tight co-ordinate regulation observed in non-clonal cultures, suggesting that these two genes operate under different sets of regulatory controls. This clonal heterogeneity may provide additional flexibility to the process of tissue repair and fibroblast clonal expansion.

Notes: Experimentally induced wounds in animal models are useful in gaining a better understanding of the cellular and molecular processes of wound healing and in the initial evaluation of the safety and effectiveness of potential therapeutic agents. However, studying delayed healing has proven difficult in animals, whose wounds heal within a few days. In this report, we describe a novel method for establishing mouse wounds that require up to more than three weeks for complete closure, and we show the validity of this model in Smad3 null mice, which are known to display accelerated healing. Full-thickness wounds, measuring 0.3 by 1.0 cm, were made down to fascia on the dorsal aspect of the mouse tail in Smad3 KO mice and control littermates, approximately 1 cm distal to the body of the animal. The wounds were left to heal by secondary intention and were assessed histologically by computerized planimetry for wound closure at various times after wounding. These wounds in wild-type mice displayed delayed healing, with full closure occurring between 14 and 25 days after wounding. Complete closure of similar wounds in Smad3 null mice healed 30% faster (p 〈 0.01). By immunostaining with ki67, a marker for proliferation, Smad3 null animals also showed increased proliferation of dermal wound cells. Cultured dermal fibroblasts from Smad3 null mice showed increased baseline DNA synthesis and, interestingly, enhanced response to TGF-β1. By Western blot analysis, Smad3 null mice fibroblasts showed a compensatory increase in MAPK phosphorylation in response to TGF-β1, suggesting that MAPK overcompensation together with loss of Smad3 may be involved in the modulation of faster healing. We conclude that this novel tail wounding model can be useful for studying delayed or prolonged wound closure.Experimentally induced wounds in animal models can be useful in gaining a better understanding of the cellular and molecular processes of wound healing. Such models have also proven themselves valuable in the initial evaluation of the safety and effectiveness of potential therapeutic agents targeted for chronic non-healing wounds. (Gottrup, Agren et al. 2000). However, no ideal animal model exists which reliably reproduces delayed healing. In the mouse, a mammal whose genome has been completely cloned and which is easily manipulated genetically, wounds normally heal within a few days, and with a great deal of contraction. (Morris, Wu et al. 1997; Gottrup, Agren et al. 2000) There are models utilizing either genetically altered and inbred mice with certain characteristics that cause delayed healing. (Carmeliet 1995) However, it would be useful to have wound healing models that are applicable to most wild type mice used as controls and which would have a large enough window of observation before healing occurs. In this report, we describe a novel method for studying delayed healing in mice. This method utilizes full-thickness wounds made down to fascia on the dorsal and mostly hairless aspect of the mouse tail. The wounds are left to heal by secondary intention and assessed histologically by computerized planimetry for wound closure at various times after wounding. In this first report, the validity of the model was determined by studying control littermates and Smad3 null mice, which have been shown to display accelerated healing. The results shown here suggest that this is a useful model for studying delayed healing in mice.

Notes: Management of surgical defects following excisional and Mohs micrographic surgery for malignant skin lesions consists of autografting, skin flaps, primary closure, and healing by secondary intention. A fully differentiated bilayered cell-based therapy (BLCT/Apligraf), expresses multiple growth factors, provides a biologically active matrix, and appears to be immunologically inert. BLCT is FDA approved for venous leg ulcers and diabetic foot ulcers. BLCT is effective in hard-to-heal venous ulcers and, in diabetic foot ulcers, it is significantly associated with less amputations and osteomyelitis. A previous open-label trial showed BLCT to be safe and effective in surgical excision wounds. However, we have been interested in rigorously identifying differences in chronic compared to acute wounds when using BLCT or other skin substitutes. In this report of a multicenter randomized study, we enrolled and treated 181 patients eligible for secondary intention healing after Mohs or excisional surgery for skin cancer, with 172 completing the study. Face wounds were excluded. In total, 84 patients were treated with BLCT and 88 with dressings alone. The primary efficacy endpoint was the quality of the healed wound using the Vancouver Burn Scar Assessment Scale (VBSAS). Pigmentation, vascularity, pliability, and scar heights were assessed by the investigator and an independent observer as 0 (no scar) to 15 (worst scar). Scores of ≤ 4 were assigned to 57 (65%) of BLCT-treated patients by both the investigator and observer, and to 60 (65%) and 54 (58%) of control patients according to the investigator and observer, respectively. There was no difference in healing time, and no severe adverse events or rapid cancer recurrence were observed in either group. In this randomized controlled trial of full thickness excision wounds after skin cancer removal, BLCT/Apligraf was safe and well tolerated.

Notes: There are only a few models for studying epidermal migration in vitro, and their interpretation is made difficult by reliance on cell monolayers and the choice of a specific substrate. In this study, the process of keratinocyte migration and epiboly were investigated by using a bilayered bioengineered skin construct, consisting of human neonatal foreskin keratinocytes and dermal fibroblasts (Apligraf, Organogenesis, Canton, MA). At baseline, 6-mm punch biopsies of the construct were placed in serum-free media (AIM-V) or DMEM with or without 10% FBS. At varying time points the bioengineered skin samples were processed and analyzed by histology and immunostaining. By 72 hours, in a time-dependent manner, the epidermis had migrated over and enveloped the entire dermis (full epiboly). Full epiboly was partially inhibited by serum and was maximal in serum-free medium. Epiboly was preserved 5 days after stated expiration date and was equivalent to that seen in unexpired construct when stored at room temperature. The process of epiboly was downregulated in a dose-dependent manner by neutralizing antibodies to EGF and TGF-beta 1. The migrating epithelium was characterized by decreased keratinocyte proliferation (as per Ki67 immunostaining) and increased expression of vitronectin (epibolin). Increasing concentrations of antibodies of vitronectin blocked the process of epiboly, as did antibodies to the alpha5-betaV integrin receptor, which mediates vitronectin-driven keratinocyte locomotion. Interesting, epiboly was also blocked by preseeding human dermal fibroblasts on the dermal side of the construct. We propose that the process of epiboly in this model can be used to better understand and assess the mechanisms involved in keratinocyte migration and may be used as an assay for establishing construct functional viability.